中国传统虾酱中产香酵母的分离鉴定及其耐盐性分析

Isolation, Identification and Salt-tolerance Analysis of Aroma-producing Yeasts from the Chinese Traditional Shrimp Paste

摘要:

虾酱是中国传统发酵水产调味品，营养丰富，并具有独特的风味。传统生产工艺周期长，产品盐度高，工艺不稳定，且存在安全性问题。为了实现传统食品的产业化需求，筛选可用于虾酱发酵的产香酵母，以提高虾酱的香气品质。本文以中国传统虾酱为原料，采用平板稀释法以马铃薯葡萄糖琼脂培养基(PDA)对虾酱中的酵母种群进行分离，经产香试验筛选得到一株产香酵母，对其进行形态观察及生理生化鉴定，结合ITS序列分析，经NCBI中数据库比对，构建菌株系统发育树明确其分类地位，确定该菌株为季氏毕赤氏酵母(Pichia gilliermondii)。对该菌株进行耐盐性分析，发现该菌株耐盐性能较好，在10%的盐度下仍有菌体存活。研究结果表明，从中国传统虾酱中分离得到的一株季氏毕赤氏酵母(Pichia gilliermondii)，不仅产香能力较强，并且具有一定的耐盐性，可对其进行耐盐驯化，作为虾酱复合发酵剂的菌株之一，用于低盐虾酱的发酵，提高虾酱发酵香气，控制产品质量。从传统虾酱中分离的产香酵母，为虾酱快速生产用复合发酵剂的制备提供了理论基础。

Abstract:

Because of the distinct flavor and rich nutrition, shrimp paste was generally consumed as a traditional Chinese aquatic seasoning. But its difficult in industrialization development was hampered because of long production cycle, high salinity, technology instability and insecurity. In order to obtain the aroma producing yeasts for shrimp paste fermentation and improve the fragrance of the shrimp paste for meeting industrialization requirement of traditional food, an aroma producing yeast was isolated from traditional Chinese shrimp paste with the method of dilution plating on the medium of potato dextrose agar (PDA) and aroma sensory analysis. The morphological identification, physiological and biochemical identification, ITS rDNA analysis and phylogenetic tree were used to identify species in this paper. By Sequence alignment from database of NCBI showed that it belonged to Pichia gilliermondii. The salt-tolerance analysis indicated that the strain could survive in 10% NaCl solution. The results showed that the aroma producing ability and salt tolerance of strain were good, and the salt-tolerance of strain could be domesticated for low-salt shrimp paste fermentation as one of shrimp paste composite starter cultures. The aroma producing yeast isolated from the traditional shrimp paste can improve the aroma and quality of fermented shrimp paste.